Indication means for light-signals.



C. S. SNAVELY.

INDICATION MEANS FOR LIGHT SIGNALS.

APPLICATION FILED 'MAY s, 1914. RENEWED APR. 7.1916.

Patented June 6, 1916.

INVEN'I'OR 6" UNITED STATES PATENT OFFICE.

CLARENCE S. SNAVELY, OF EDGEWOOD BOROUGI-I, PENNSYLVANIA, ASSIGNOR TO THE UNION SWITCH & SIGNAL COMPANY, OF SWISSVALE, PENNSYLVANIA, A CORPO- RATION OF PENNSYLVANIA.

Specification of Letters Patent.

Application filed May 8, 1914, Serial No. 837,189. Renewed April 7, 1916. Serial No. 89,726.

To all whom it may concern:

Be it known that I, CLARENCE S. SNAVELY, a citizen of the United States, residing at Edgewood Borough, in the county of Allegheny and State of Pennsylvania, have invented certain new and useful Improvements in Indication Means for Light-Signals, of which the following is a specification.

.My invention relates to signals and particularly to signals of the type in which electric lamps are employed for giving indications. 7 p

More particularly the invention relates to means for indicating whether or not a lamp is illuminated. Y

My invention is particularly adapted for use in connection with signals of the type in which two or more lamps are used for giving two or more distinctive indications, which lamps are controlled by a circuit controlling lever, which is usually one of a plurality of levers comprised in an interlocking machine. n

I will describe certain forms of apparatus embodying my invention and will then point out the novel features thereof in claims.

In the accompanying drawings, Figure 1 is a view showing diagrammatically one form of apparatus embodying my invention. Fig. 2 is aview showing a modified form of relay which may be employed in connection with the apparatus shown in Fig. 1.

Referring first to Fig. 1, S designates a signal comprising, as here shown, three incandescent electric lamps L L and L, which lamps are at times supplied with current from the secondary of a transformer M, whose primary is connected with a suit able source of alternating current, not shown in the drawing. The supply of current from transformer M to the lamps of signal S is controlled by contacts operated by a manually operable lever H. Each lamp is provided with a lens 27 for projecting a beam of light from the lamp. The lamps L L and L3 are adapted to indicate clear, caution and danger respectively, and for this purpose the beams projected by the lamps preferably differ in color, being usually green, yellow and red respectively. p,

As here shown, I provide a transformer for each lamp, which transformers are designated respectively'by E, F, and G,'each lamp being connected with the secondary of the corresponding transformer, and the pri* mary of each transformer being connected at times with the secondary of transformer M. When the lever H is in one extreme position, whichI will herein term the normal position, and which is the position in whicn it is shown in the drawing, transformer (5r forlamp L isl supplied with current from the transformer M, the circuit being from one terminal of the secondary of transformer M, through wire 5, contact block J on lever H, contact 6, wire 3, primary of transformer G, wires 7, 4: and 8 to transformer M. The lamp L is, therefore, illuminated and lamps L and L are extinguished, because wires 1 and 2 are not in contact with block J on lever H.

When itisdesired to illuminate lamp L", the lever H is moved in the direction indicated by the arrow until block J engages contact 9, thereby closing thecircuit through the primary of transformer F which circuit is ,similar to that hereinbefore traced for transformer G. It will be seen that this movement of lever I-I disengages block J from contact 6, so that lamp L then becomes extinguished. When it is desired to illuminate lamp L the lever H is moved still farther in the direction indicated by the arrow until block J reaches contact 10, thereby closing a circuit. through transformer E G, which circuit is similar to the circuit hereinbefore traced for transformer G'E.

As stated hereinbefore, thelever H is usually one of aplurality of similar levers em-v bodied in an interlocking machine, and as is well understood in the art, it isdesirablethjat the complete return of the lever to its normal position should be prevented until the signal' S shall have changed to danger indication, that is, until lamp L shall have become illuminated and lamps L9 and L? extinguished. To accomplish this,I provide a dog 11 on lever H, which dog coacts with a latch 12 controlled by a magnet K. It will be seen that the latch12,

Patented June 6, 1916.

becauseof the inclined face of the dog, does with dog 11' and the' return movement can- 1 1617 be completed" untilmagnet K is ener gized. Magnet K is controlled by a relay D, which is in turn controlled by current in the circuits of lamps L L and U. The relay D, as here shown, comprises a fixed winding 19, a movable winding 13, and a contact controlled by the latter winding. As here shown, the control of relay D is accomplished by transformers A, B and C, whose primaries are included in series respectively with lamps L L and L and whose secondaries are connected in series and also with one winding 13 of relay D., The circuit for this relay winding is from one terminal of the secondary of transformer A, through wire 14, secondary of transformer 13, wire 15, secondary of transformer C, wire 16, contact N, contact block I on lever H, wire 17, relay winding 13, wire 18 to secondary of transformer A. The other winding 19 of relay D is energized from transformer M, the circuit being through wires 8 and 20, winding 19, wire 21, to secondary of transformer M.

When the return movement of lever H is arrested by latch 12, contact block J is in engagement with contact 6 and contact block I is in engagement with contact N, so that the circuits for the lamp L and wind ing 13 are complete. If current is then flowing through lamp L transformer C is energized thereby, so that current is sup plied (to winding 13 of relay D, and the phases'of the currents in the two windings of relay D are then such that contact 2222 of this relay is closed, thereby causing magnet K to be energized by the following circuitfrom battery 23, through wire 24:, magnet K, wire 25, contact 2222"-, and wire 26 to battery 23. Magnet K then raises latch 12 out of path of dog 11 so that the movement of lever H can be com pleted. This completion of the movement opens contact NI so that the consumption of energ r by relay D is stopped.

It will be noted that the circuit for winding 13 of relay D includes the secondaries of the three transformers A, B and G, and that the secondaries of A and B are con-- nected in this circuit in the opposite direction to the secondary of transformer 0. Hence, if by accident one of the lamps L or L should continue to be illuminated at the same time as lamp L, the current de livered to the circuit of relay winding 13 by transformer A or B would be in the opposite direction (considering instantaneous values) to that delivered by transformer C, so that these currents would neutralize eachother and relay D would not be energized. Furthermore, if all three lamps should be illuminated. at once, then the resultant current supplied to relay Winding 13 would be in the opposite direction to that supplied by transformer C, and this relay would be energized in such direction as to positively hold its contact 2222 open, so that the latch 12 would not be operated to release lever H. Inasmuch as the current flowing in the lamps L L and L is rather small, the transformers A, B and C are pref erably of the step-up variety in order to make the voltage at the terminals of 1 and 13 of relay D sufiicient to operate this relay satisfactorily.

In Fig. 2 I have shown a modified form of relay D which may be substituted for relay D in Fig. 1. This relay is the same as relay D, except as to the contact members. Connected with the movable member 13 is a block 28 of insulating material in which are fixed two contact fingers a and Z), the former of which is stiff and the latter flexible. Both of these fingers are adapted to make contact with a bridgingcontact block 7 which is carried by a spring (Z. The parts are so proportioned that when the relay is energized, finger 7) touches block 7 before finger a. Finger a is connected with Wire 25, and finger b with wire 26. When the lever H is returned to the point where it is stopped by latch 12, if the normal current is flowing in lamp U, the torque of relay D will be such that both fingers a and I) touch block 7, so that the circuit for magnet K will be closed. If, however, the current in lamp L should be below the normal value, the torque of relay D will not be sufficient to bend finger Z) enough to permit finger a to touch block f, so the circuit for magnet K will not be closed. And if the filament of lamp L should be short-circuited, the current in transformer C would be above the normal value, and the torque of relay D would then be such that finger a would move the block 7 away from finger 7 b, the latter being held by a stop 0.

Although I have described only certain forms of apparatus embodying my invention, it is understood that various changes and modifications may be made therein within the scope of the appended claims, without departing from the spirit and scope of my invention.

Having thus described my invention, what I claim is:

1. A signal comprising a plurality of electrio lamps, means for supplying alternating current to said lamps, a transformer for each lamp the primary of each transformer being connected in series with the corresponding lamp and said transformers being so arranged that the current delivered by one of them. is opposite in phase to that delivered by the others, and indicating means comprising a device responsive to reversals of phase and controlled by the current delivered by said transformers.

2. In combination, a signal comprising a plurality of electric lamps, a source of alna i g current, a circuit controlling lever for controlling the supply of current from said source to said lamps, a transformer for each lamp, the primary of each transformer being connected in series with the corresponding lamp and said transformers being so arranged that the current delivered by one of them is opposite in phase to that delivered by the others, an indicating device for governing a movement of said lever,

and means responsive to reversals of phase and controlled by the current delivered by said transformers for contolling said indicating device.

3. A signal comprising a plurality of electric lamps, means for supplying alternating current to said lamps, a transformer for each lamp the primary of each transformer being connected in series with the corresponding lamp and said transformers being so arranged that the current delivered by one of them is opposite in phase to that delivered by the others, and indicating means comprising a device responsive to reversals of phase and controlled by the current delivered by said transformers, said device being effectively responsive to the normal value of the current delivered by one of said transformers but not to a current above or below said normal value.

In testimony whereof I afiix my signature in presence of tWo Witnesses.

CLARENCE S. SNAVELY.

Witnesses: V

A. HERMAN WEGNER, R. L. KIs'rLER.

Copies of this patent may be obtained for five cents each, by addressing the Commissioner of Iateltl,

' Washington. D. G. 

